The board for gliding on snow forming the snowboard is used asymmetrically, with the user having neither the body nor the feet directed on the longitudinal axis of the board, but placed at a considerable angle relative thereto. The user's body is placed transversely relative to the board, and either the right foot behind and the left foot in front for people who steer with the right foot ("regular foot") or else the left foot behind and the right foot in front for people who steer with the left foot ("goofy foot"). The spacing between the feet depends on the morphology of the user, and essentially on the size of the user. The toes are directed more or less towards the front of the snowboard, at an orientation which is expressed as an angle measured from the perpendicular to the longitudinal axis of the snowboard. For the back foot, this orientation generally lies in the range about 0 to 45.degree., and for the front foot in the range 10.degree. to 45.degree., the position presently most in favor with numerous skilled users being an "intermediate" position:
back foot: angle of orientation lying in the range 10.degree. to 15.degree.; and PA1 front foot: angle of orientation lying in the range 30.degree. to 45.degree.. PA1 the "4.times.4" configuration which is the most widespread and which comprises two zones (one for each foot) each having eight holes, these holes being spaced apart at 40 millimeters from one another and being distributed in two parallel columns of four holes each. These eight holes are generally drilled and tapped in the snowboard in advance; and PA1 the triangular configuration known as "3D" from the trademark filed by BURTON, and to be found on snowboards and bindings from that company. PA1 a gliding surface made up of a glide soleplate between metal edges; PA1 one or more bottom reinforcing layers; PA1 a core; PA1 one or more top reinforcing layers; and PA1 a protective and decoration-carrying sheet made either as a shell and thus constituting the top and the sides of the board, or else existing solely on the top surface of the board, in which case it rests on protective elements running along the sides of the core and referred to as flanks; PA1 the top face of the snowboard presents a substantial middle longitudinal depression which extends over at least the two zones in which the bindings for the feet are positioned, respectively for the front foot and for the back foot of the user, thereby defining on either side thereof two longitudinal lateral spars; PA1 anchor points are provided in said two longitudinal lateral spars; and PA1 an intermediate device which is received in said anchor points serves to hold the user's feet to the board. PA1 firstly towards the front and back margins which are to cover the right and left lateral portions of the snowboard in said binding-positioning zone, anchor means for anchoring said plate in said right and left lateral portions of the snowboard, said means for anchoring to the snowboard thus being located respectively at the front and at the back of the foot of the user; and PA1 secondly, in its central zone that is therefore designed to overlie the middle zone of the snowboard, binding receiving and anchoring means provided to coincide with the orifices that exist for this purpose in said binding, said binding anchoring means thus underlying the arch of the sole of the user's foot. PA1 at the back of the plate: at least one slot or series of at least two holes situated under the back of the boot that is to be received and thus under the heel of the user; and PA1 at the front the plate: a series of at least two elongate and rectilinear slots situated under the front of the boot to be received and thus under the front of the user's foot, each being oriented towards the central region of the plate, the slots being dimensioned so that in the event of the snowboard flexing, they allow front anchor members for anchoring said baseplate to the snowboard to slide freely therein. PA1 wherein said binding has two distinct portions that are separate from each other, namely a front portion which is fixed to the snowboard on its front side and which receives said front strap, and a back portion that is thus independent of the front portion and that is fixed to the heel or back side of the snowboard, and which receives the back strap.
In any event, the body of the surfer extends transversely relative to the board and its travel direction. Turns are performed either by leaning the body forwards, i.e. towards the toes (commonly referred to as "front-side") or by leaning the body backwards, towards the heels (or "back-side").
Snowboards are nowadays exceptionally popular, particularly with young people, such that snowboarding competitions are now being organized like skiing competitions, with the "speed" factor becoming essential for snowboards that are intended for competition, as is also the capacity of such snowboards to turn with maximum precision.
This enthusiasm for snowboards is also reaching people other than the young, and as a result it is also becoming necessary to provide ladies' snowboards having good qualities of lightness and comfort, and also snowboards for the general public having good comfort without excessively penalizing effectiveness and light weight.
In general, the board for gliding on snow that constitutes a snowboard must be sufficiently stiff, when flexed while flat, to penetrate as little as possible into the snow and thus to glide as fast as possible without being so stiff as to leave traces of its edges in a curve while turning.
It is therefore necessary for the board to be as stiff as possible when flat, and as flexible as possible when tilted, i.e. when it is inclined and resting on an edge.
These two conditions are contradictory, and the art of the makers of boards for gliding on snow for snowboards consists in finding the best compromise between stiffness and flexibility that makes it possible simultaneously to move fast when the board is flat and also to make turns easily and accurately.
An additional problem lies in the fact that the board constituting such a snowboard is relatively wide, it is generally quite heavy, and that is unfortunate.
Another parameter that it is important to control is the lateral stiffness of the board, i.e. the stiffness which is exerted on the snowboard when it is placed flat on a horizontal slab, and then a laterally-directed force is applied to the middle point of the snowboard. To make it possible to obtain good accuracy in path followed, it is important for the snowboard to be very stiff laterally so as to avoid changing the shape of its side, i.e. the curved shape followed by each of its edges.